Once Upon a Time, I was a Demon Lord
by Suifeng Crimes
Summary: He knew he was one of Fate's Fools and was the Demon Lord in his past life, but he didn't need the whole 'you're the single most evil being' drama from the Heroes right now.


Disclaimer: I do not own KHR, or any of its characters.

* * *

" _My Lord, please leave!"_

' _Desperate eyes._ ' He gave his second in command a gentle smile, then a look of resolve.

" _I will not leave my subjects behind!"_

He declared so readily. It stunned his friends- it stunned the whole court. Again, they weep for the inevitable loss of their most diplomatic and most successful ruler in their history. His compassion brought them to this moment, raised them from the ashes, and gave their kingdom prosperity.

The Demon Lord gives his companions gentle smiles once again… then he ordered all of them to leave, escape. He and his army will stall the Heroes and give them time to escape. He declares his second in command as the new ruler if he falls. No one bothered to mention the silent 'when he falls'.

" _I will strike you and your oppression down!"_

He gave the Heroes a smirk, and it nearly falters upon seeing one of them. One who had seen how he ruled. The only one who was aware of his true nature, his compassion, his love and loyalty to the people that were not his kin in the first place. Nevertheless, he pressed on. It would not do any of them good if he falters now. His one last act against the human race, one last act for the betterment of his (not quite) people.

" _Ha! Who do you think you are, you_ _ **insignificant beast**_ _?!"_

He now stood in front of his subjects, he precious, precious people. He stood proud, even if the hero had essentially brought him out to display his death to them. Maybe to discourage his people from ever having a ruler like him. To cut their hopes and destroying their wills and their fire.

This was the heroes' mistake.

" _No matter what happens, even if the humans push us down, again and again, even if I die here… The Demon Race will never bow their heads to the humans!"_

Simple, he hummed in content, then announced.

" _LONG LIVE THE DEMON RACE!"_

His people stirred at his ministrations. They started with hopes, which then developed into thoughts, to whispers, to words, and then they yelled out.

" _LONG LIVE THE DEMON LORD!"_

" _LONG LIVE THE DEMON RACE!"_

" _ **LONG LIVE THE DEMON LORD!**_ _"_

Their words reach him, his ears, his mind, his soul, his heart. They touched him, and his compassionate amber gaze, his peaceful, satisfied smile, and his bleeding chest were the very last image his precious subjects had of him.

Their cries were faint to his ears and he wished he could reach his hand out to wipe the tears that were surely running on their faces. To comfort them, to tell them that _he will be okay, he will live on within their hearts and souls_.

Then he awoke into the hellhole that was his life before a desperate Demon Lord without an heir summoned him to Astaroth, the capital of the Demon Kingdom.

There, one Sawada Tsunayoshi, physically of age 12 but mentally of age 27, wept for the loss of his former life, one that had been better even though he was the Demon Lord. Even though he was the villain in every adventure story. He prayed that Maferath will lead without the thoughts of revenge against the humans, prayed that his people will not hold his death against the misguided fools that were the Heroes… prayed for the one Hero to be accepted into her group even after openly weeping for his death.

Tsuna was inconsolable for weeks after that.

* * *

It has been two years since Reborn had trained Sawada Tsunayoshi. First as Vongola Decimo, then as Neo Vongola Primo. He observed the sleeping figure of his student, contemplative as he recalled the events of the first two years.

At first glance, Sawada Tsunayoshi was everything the CEDEF Advisor's file said. He was clumsy, slow, indecisive, and a coward. His prospects as a candidate was low- lower than the possibility of the kid spontaneously sprouting wings and horns.

However, as time grew, Reborn witnessed his student's exponential growth. Choosing his Guardians- his Family over winning. Reacting to his first kill in a much better way than he expected from a civilian. Forgiving even his worst enemies when they proved to be capable of change. Fighting against a betrayal- and still forgiving the traitors. Fighting for him, fighting against him _for him_.

Finding a cure for the Arcobaleno (because that system was a disease, and even Checker- _Kawahira_ knew it).

Reborn paused, and thought a little longer on that last sentence. He recalled how his charge had merely stood against Kawahira. How his figure seemed larger, despite not having grown spontaneously, how the air around him grew heavy, how his presence demanded respect and fear. The Earthling may deny it all he wanted, but everyone saw how he had opted to stand in attention under the force that was Tsuna. In fact, everyone had done the same thing.

Tsuna had given Kawahira a glare that dared to go against his authority, yet his stance was relaxed. It was not a battle of wills- no. Everyone's breaths had become stuck in their throats as they watched Kawahira, watched as the Vongola Decimo to-be pinned the other down with merely his presence and a look. A look that had given a silent threat of punishment if the man moved even an inch.

They kept at that until Talbot had arrived.

The old man gave Tsuna a knowing look, and the latter had blushed in embarrassment, a certain guilt that flashed across his eyes- as though Tsuna was guilty for something that he had done. The interaction irritated Reborn, who disliked not knowing anything.

Reborn made sure to punish his student the next day. Using the Dying Will Bullet and getting him to confess to Kyoko, of course.

(Of course, Reborn was not jealous. There was no need to be jealous. Reborn does not _do_ jealous. Especially not over a boy that he will leave when he had finished this tutoring job.)

Tsuna grinned stupidly at him after the whole ordeal, and Reborn made a mental note to quadruple the kid's training regime. If said kid had shivered almost immediately after the thought, Reborn paid no heed.

Back to the present, Reborn returned to staring at Tsuna's sleeping form. He smirked as he thought about the boy's reaction when he wakes up in Italy hours later. He was slowly lulled to sleep by the plane's humming; he might as well get some shuteye.

Softly glowing amber eyes watched him as he fell asleep.

* * *

Tsuna is seventeen when, in the middle of class, one of the soldiers of Vongola entered to give him something wrapped in dark coloured silk. The parcel was simply left on his table before the soldier left hastily, giving Tsuna, or any one for that matter, no time to react.

Hayato ran to catch up to the soldier, to teach him about a thing about disrespecting the Tenth, the words on his lips dying when he found no signs of the soldier. Tsuna asked Hayato to return to him and told him to stay at a safe distance away from the package as he opened it. Hayato opened his lips to protest- but it died when Tsuna gave the bomber a reassuring smile.

Takeshi stood aside at Tsuna's request, around the same distance with Hayato. His Left and Right gave each other the same alarmed look. There was something about the package that, oddly enough, their boss was not picking up. A danger? A change? None of them was too sure, but if Tsuna had not given them any indication that the package was harmful then they will stand down and wait patiently.

Tsuna unwrapped the package, ignoring the curious gazes of his classmates. His eyes widened at the familiar motif of navy and gold intertwining. His hands hastened, quick and expectant like a child who had just been told that it was okay to open his birthday gift. He ignored his nails sharpening and blackening, just to feel the familiar power surging through him and-

" _Alas, I have found you, my one true King, Lu-_ "

Tsuna smiled, content, as he twirls his midnight blue pistol. He felt at home, like his body was finally _his_. Specks of amber dance with the brown within his orbs, his canines slightly sharper, and his nails were a permanent black (Tsuna mentally wailed, how was he going to explain _**that**_ to Reborn?). His hair hid the small horns that had definitely sat atop his head, and Tsuna could feel the invisible power and weight of his six individual wings. It was _heaven_ ; it was a form that his death as Lu***** had denied him when he returned to his original twelve year old body as consequence.

Tsuna doubted that he would be tripping anything anytime soon.

Everyone watched in shock as the gun simply transformed into a simple, yet elegant, fountain pen. Hayato's eyes shined when he saw that Tsuna had acquired an item that definitely was not of this world. Takeshi scratched the back of his head as he wondered how Reborn would take the fact that Tsuna had a shapeshifting _weapon_.

"What are you staring at?" Tsuna asked, warm and polite, yet it sent shivers down their spines. They looked away, ignoring it. No one would even speak of the incident, not even the Decimo's Rain and Storm. They all understood his request and his threat.

After all, what happens in Vegas stays in Vegas.

* * *

Honestly, Tsuna thought that the Heroes' arrival would have come to him a lot earlier. Considering he was one of Fate's official Fools, which Abyss- his symbol of power that often manifests himself as a fountain pen or a pistol- had confirmed, the whole shit about 'mind controlling his friends' and 'what is your agenda' from these four individuals would have gotten to him sooner. Tsuna thought for a moment that, maybe, just _maybe_ , that Fate wanted to give him a break before he disregarded it. Even Abyss agreed that it was most likely to screw with him.

Nevertheless, Tsuna did not want to deal with the fucking drama in the middle of his debut as Vongola Decimo.

"Please, ladies and gentlemen, if I had truly caught my friends in a mind control, the Mist Arcobaleno and my Mists would have caught it." His smile was straining, his eyes were about to turn _molten gold_ , and Tsuna wondered if this was karma for all the times he casted that same mind control spell to stop servants from letting him escape into the human kingdom once in a while.

Enraged red eyes glared at him, but the effects of said glare bounced off his skin. ' _How utterly terrifying,_ ' Tsuna thought, definitely thinking about how a ten year old human girl who was working her ass off to help her younger siblings live a comfortable and successful life was more intimidating than this. His lips formed an amused smile as he eyed his guests.

They were becoming paler and paler as three out of four idiots ranted on and on about how he was the despicable Demon Lord or about how he personally beheaded three generals. The fact that they did not go into specifications made everything a lot easier for him.

Tsuna's eyes connected with the fourth, very uninterested, member of the group. The girl sighed in misery, mouthing an apology to him. She had only been the one to go out of her way to get to know him, both as Lu***** and as himself. Tsuna thought about the strings he had to pull in order to get her, and _only_ her, into Vongola. She made for a good spy, a great assassin, and an even greater friend. Maybe an understudy for a consigliere? Alternatively, and if Reborn was willing, get her into the CEDEF as the Arcobaleno's right hand? Her actions tonight definitely showed that she had the physical and mental capacity for the position.

When the three Heroes had decided to don their 'Holy' garments, Tsuna knew that playtime was over. The Assassin Heroine had slowly inched towards the buffet during the whole ordeal before her supposed teammates' actions, and he could even see her shoving a few foods into her hammerspace that all five of them have.

"Now, now, don't get too hasty," he said, "May we do this outside the mansion? This building had stood for over 400 years and I wouldn't want Primo to haunt me for its destruction." Tsuna gave his Guardians, except for sweet Chrome, a pointed gaze; all its recipients flinched at the look. "And we get to settle this with no casualties from the onlookers!" Tsuna exclaimed.

"… You have a point," his arch nemesis (not that Tsuna really thought him as one) agreed grudgingly. Tsuna smiled serenely, it was always amusing to reason with the Heroes' morality.

"Okay, good." Tsuna laughed breathily, his wrists rolling lazily, "I'll be waiting."

Tsuna promptly vanished.

" **WHY DOES HE ALWAYS FUCKING DO THIS AT EVERY DAMN FIGHT?!** "

The Assassin Heroine laughed heartily as she transported the whole group to the plain Tsuna had mentioned. It was true. Tsuna had the ability to teleport without any incantations or a magic circle. ' _No,_ ' she thought as she surveyed the flat piece of land, ' _The Demon Lord Lu***** had the most precise magic control within Elysium and he was the strongest being in the whole_ world _. The only reason why we were able to behead him was most likely because he had done his job: save his people._ '

She smiled and quickly returned to the mansion. She vowed not to participate in a death battle with the Demon Lord after that half-hearted boss fight. The Assassin was absolutely delighted when a huge flat screen TV dropped from above. She wanted to see her ex-friends struggle to survive the wrath of one Sawada Tsunayoshi. The Assassin _did_ recall a few choice words from the trio about the Demon Lord's friends and family.

"What's happening?" She heard someone asked, and she grinned manically.

"This is a public execution!" She announced, "A performance that will tell the Cosa Nostra- no- the _whole_ **world** what will happen if you pissed off Sawada Tsunayoshi, Vongola Decimo and the world's most powerful being." Everything she said was true and it would not be her fault if the mafia tonight will go home bearing nightmares of the Vongola Decimo.

The Assassin munched on her popcorn, ignoring the questions aimed at her by the Vongola Famiglia.

Meanwhile, Tsuna inserted his hands into the pockets of his pants. The Three took this as a signal that the battle was beginning and lowered into their stance.

Almost immediately, as one does not train with the Arcobaleno and the Seven Deadly Sins without noticing any of these, Tsuna spotted multiple openings, some of which were new.

' _Rusty,_ ' Tsuna thought, his lips pulling into a ruthless smirk, ' _They never had a chance to practice in their civilian lives- and The Assassin had thrown herself into the world of crime to make sure she doesn't forget her lessons._ ' He kept his stance relaxed, smirk still in place. This posture and expression irked his opponents, Tsuna knew for sure, and Reborn was either going to roast him for it or tor- ahem- train him into irritating his enemies better.

"What are you waiting for?" Tsuna asked, tilting his head, "A monologue of my _despicable_ deeds? My so-called 'evil plans'? Or do you need a signal to attack me first?" He looked up, thinking about it. "Or maybe," he said, "You all have come to the conclusion that fighting against me is not just a meaningless fight but it is also a _losing battle_?"

Tsuna laughed as he tilted his body to avoid the Healer that had suddenly charged at him. He moved around his attacks fluidly, as though one evasion was merely an action in preparation for the next move. He caught the blade that the Warrior had brought down upon him and pushed it away effortlessly. The fireball aimed at him merely dissipated before it could even touch him. Tsuna wondered if doing this would only make the Heroes in front of him stronger, before shaking his head. Only the Assassin had that ability- claiming her as the one true leader of the Four Heroes, but Spasenie's royalty were judgemental idiots and delegated the leader role to the Warrior. In fact, both he and the Assassin had that indestructible plot armor.

"Are you even trying your best?" Tsuna drawled, "Man, I must have been a weak idiot to lose against you three." He grinned when that fueled the flames of hatred within these idiots' eyes. Every good warrior knows that you should not allow your emotions to rule over your decisions, unless they are your weapons.

Tsuna decided to go from a defensive position to a more offensive approach. He kicked the Warrior's armoured chest, sending the fool to the sky. He caught the Healer's hand and threw him into the ground (making him unconscious), then easily decimated the barriers that surrounded him.

"Excalibur must have been distraught to have a master as unskillful as you are," Tsuna commented just as he shifted just a bit from his position, "Or Merlin may be utterly disgusted by how easily you were fooled into thinking that Tartaros was a kingdom of bloodthirsty demons that waged wars for shits and giggles."

The Warrior growled at him and immediately went into his final form. The Mage, who had gone on to wake the Healer up, followed his lead. The Healer too, once the poor man regained his wits. Tsuna allowed him, allowed them, to recover. He assembled a pistol within the timeframe, loading it with bullets just as the last of the group had finished his transformation.

Tsuna was impressed with their combined auras, ' _They, as a group, could take down one of the low-level generals._ ' He hummed as he removed the safety of his gun. This, with the help of his overpowered magic, will be enough. Their newfound powers might have been greater- had Tsuna thrown all of his best at them every time they attacked his armies. Except, Tsuna was not an idiot and had told all of his generals that once a Hero is sighted, they were to retreat and never engage on a battle with them. Their powers must have come from dungeons and grinding them.

"Let me show you how useless all your efforts would be," Tsuna said, a Reborn-like smirk on his face, "And show the whole Cosa Nostra what happens when you piss off a retired Demon Lord."

To say that the Three had survived the massacre that followed the declaration would be lying.

When Sawada Tsunayoshi returned to the party thirty minutes later, he looked as though not a single hair on him was tousled. His clothes deceptively immaculate- his orange dress shirt was clean of the blood everyone knows the rest of his suit had.

The Assassin smirked at him, "You should have shown your actual Demon Lord form," she said, to which Tsuna waved a hand dismissively.

"Abyss would turn on me if I used that form to end your ex-teammates' existences," Tsuna said, and smiled at his friends, "And you will get your explanation once this party ended."

The party continued on, everyone in it completely revising their impression of Sawada Tsunayoshi.

* * *

"Dame-Tsuna, explain."

Reborn held a gun to his head as Tsuna laughed. He was finally alone with his inner circle plus the Assassin. The woman merely gave him an amused look when he glanced at her for assistance.

"The Four Heroes were summoned a year before your defeat," she said, her hand raised in the universal language of surrender, "For whatever happened within the century you were in power and your summoning is on you." Her silver eyes scanned the room, "If you want, I can put up a barrier and you can transform into that Demon Lord form. I want to see you wearing a crown and a braid again."

Tsuna accepted the offer and thanked the Assassin once she set up the barrier, then he released his restraints on his Demon form.

"I can't get out of this, can I?" he asked as he sighed, plopping unto the throne that appeared with his transformation.

"No," was Reborn's frank reply.

Tsuna sighed again, wishing that he were not one of Fate's Fools. Then again, there was always at least one Fool in one universe. He was the Fool of this universe, the main Fool at least. It was quite obvious- more so when Reborn had barged into his life. He also wished, as futile as it was, that Fate was not so openly sadistic about this. He was sure that he was not the only one who was complaining about Fate handling her Fools roughly.

When Tsuna felt pain hit his head, thanks to the Leon mallet his tutor seemed to be fond of, he knew he was prolonging the inevitable.

Tsuna sighed once again. The sooner he finishes this, the better. (Especially when he could _feel_ his paperwork increasing like bacteria with every second wasted.)

"Once upon a time, I was a Demon Lord…"

OWARI

* * *

Author's note: This had been bugging me shortly after I started writing _**From Sky to Cloud**_. You'll see me continuously referring Tsuna as one of Fate's Fools within my stories. One of them because he isn't the only that has to endure Fate's whims.

I hope you enjoyed this!

Thank you for reading!


End file.
